Downregulation of cyclooxygenase-2 expression and activation of caspase-3 are involved in peroxisome proliferator-activated receptor-γ agonists induced apoptosis in human monocyte leukemia cells in vitro

2006 ◽  
Vol 86 (3) ◽  
pp. 173-183 ◽  
Author(s):  
Jia-Jun Liu ◽  
Pei-Qing Liu ◽  
Dong-Jun Lin ◽  
Ruo-Zhi Xiao ◽  
Min Huang ◽  
...  
2009 ◽  
Vol 28 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Jia-Jun Liu ◽  
Ting Hu ◽  
Xiang-Yuan Wu ◽  
Chun-Zhi Wang ◽  
Yan Xu ◽  
...  

This study investigates the ability of a synthetic PPAR-γ agonist, rosiglitazone (RGZ), to induce apoptosis in leukemia K562 cells. The results revealed that RGZ (>40 mmol/L) inhibits the growth of K562 cells and causes apoptosis in a time and dose-dependent manner. Apoptosis is observed clearly by Hoechst 33258 staining. Western blotting analysis demonstrates the cleavage of caspase-3 zymogen protein with the appearance of its 17-kD subunit and a dose-dependent cleavage of poly (ADP-ribose) polymerase. Furthermore, RGZ treatment down-regulates anti-apoptotic protein Bcl-2 and up-regulates pro-apoptotic protein Bax in a dosedependent manner after the cells are treated for 48 hours. Telomerase activity is decreased concurrently in a dosedependent manner. We therefore conclude that RGZ induces apoptosis in K562 cells in vitro, and that RGZ-induced apoptosis in K562 cells is highly correlated with activation of caspase-3, decreasing telomerase activity, down-regulation of the anti-apoptotic protein Bcl-2, and up-regulation of the pro-apoptotic protein Bax.


PPAR Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jilong Hu ◽  
Zhinan Zheng ◽  
Jia Lei ◽  
Yuxin Cao ◽  
Qiyun Li ◽  
...  

Enhancer of zeste homolog 2 (EZH2) is abnormally highly expressed in pancreatic cancer (PC). However, it is not ideal to treat PC by inhibiting EZH2. This study reported that the combined use of pan-peroxisome proliferator-activated receptor (PPAR) agonist could significantly improve the anti-PC effect of EZH2 inhibitor. In vitro, PC cell lines PANC-1 and AsPC-1 were cultured, and MTT and flow cytometry were performed to observe the effects of pan-PPAR agonist bezafibrate and EZH2 selective inhibitor GSK126 on cell viability and apoptosis. In vivo, CDXs of PANC-1 and AsPC-1 were established to observe the effects of bezafibrate and GSK126 on bearing tumors. Western blotting was performed to detect the protein expressions of H3K27me3, β-catenin, p-β-catenin, cyclin D1, c-Myc, and cleaved caspase 3 in vitro and in vivo. The results showed that bezafibrate significantly improved the effects of GSK126 on proliferation inhibition and apoptosis promotion in vitro and the growth suppression of CDX tumors in vivo. It also significantly enhanced the effects of GSK126 on upregulating the expression level of p-β-catenin and that of cleaved caspase 3 in vitro and in vivo. In parallel, downregulation of the expression levels of H3K27me3, β-catenin, cyclin D1, and c-Myc was also observed in vitro or in vivo. These results suggest that the combination of bezafibrate and GSK126 has synergistic effects on PC, and the molecular mechanism may be related to the enhanced inhibition of the Wnt/β-catenin signaling pathway. We believe that targeting the EZH2-PPAR axis is a potential therapeutic pathway for PC.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4377-4377
Author(s):  
Joo-In Park ◽  
Hoon Han ◽  
Ji-Seon Han ◽  
Hyuk-Chan Kwon ◽  
Jin-Yeong Han ◽  
...  

Abstract Imatinib (STI571, Glivec) is the choice treatment for Bcr/Abl-positive malignancies. Emergence of resistance to Imatinib warrants the exploration of novel well-tolerated anticancer agents. Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor family, which mainly associates with the adipocyte differentiation, but also appears to facilitate cell differentiation or apoptosis in certain malignant cells. Previous studies imply that the PPARγ activation pathway may be a possible intervention mode for treatment of leukemia, which is resistant to imatinib (STI571). In this study, we investigated the effects of pioglitazone, a synthetic ligand for PPARg, on the cell growth and TRAIL-induced apoptosis in a novel imatinib (STI571) resistant acute myeloid cell line (SR-1), which we have established from an STI571 resistant blast crisis patient, as well as HL-60 cells. HL-60 and SR-1 cells are relatively resistant to TRAIL-induced apoptosis. Pioglitazone alone inhibited the cell growth of SR-1 and HL-60 cells, but did not induce the apoptosis of these cell lines. However, simultaneous exposure of cells to 100 ng/ml TRAIL with either 25 μM pioglitazone or 50 μM piogliazone resulted in a striking increase in apoptosis. To clarify the mechanism of pioglitazone to sensitize the leukemia cells to TRAIL-induced apoptosis, we investigated the change of the proteins related to cell cycle and apoptosis by western blot. As results, we observed the significant decrease of X-linked inhibitor of apoptosis (XIAP) and the increased expression of p21 by cotreatment of pioglitazone with TRAIL. Taken together, these findings indicate that pioglitazone may have promising activity in augmenting TRAIL-induced apoptosis of human acute leukemia cells including the imatinib (STI571) resistant acute myeloid cell line.


Author(s):  
Lisa Kater ◽  
Benjamin Kater ◽  
Michael A. Jakupec ◽  
Bernhard K. Keppler ◽  
Aram Prokop

AbstractDespite high cure rates in pediatric patients with acute leukemia, development of resistance limits the efficacy of antileukemic therapy. Tris(1,10-phenanthroline)tris(thiocyanato-κN)lanthanum(III) (KP772) is an experimental antineoplastic agent to which multidrug-resistant cell models have shown hypersensitivity. Antiproliferative and apoptotic activities of KP772 were tested in leukemia, lymphoma and solid tumor cell lines as well as primary leukemia cells (isolated from the bone marrow of a child with acute myeloid leukemia (AML). The ability to overcome drug resistances was investigated in doxorubicin- and vincristine-resistant cell lines. Real-time PCR was used to gain insight into the mechanism of apoptosis induction. KP772 inhibited proliferation and induced apoptosis in various leukemia and lymphoma cell lines in a concentration-dependent manner (LC50 = 1–2.5 µM). Primary AML cells were also sensitive to KP772, whereas daunorubicin showed no significant effect. KP772 induces apoptosis independently of Bcl-2, Smac, and the CD95 receptor and is also effective in caspase 3-deficient MCF7 cells, indicating that apoptosis is partly triggered independently of caspase 3. mRNA expression profiling revealed an upregulation of the BH3-only Bcl-2 protein Harakiri in the course of KP772-induced apoptosis. Remarkably, KP772 overcame drug resistance to doxorubicin and vincristine in vitro, and the apoptotic effect in resistant cells was even superior to that in non-resistant parental cells. In combination with vincristine, doxorubicin and cytarabine, synergistic effects were observed in BJAB cells. The cytotoxic potency in vitro/ex vivo and the remarkable ability to overcome multidrug resistance propose KP772 as a promising candidate drug for antileukemic therapy, especially of drug-refractory malignancies.Graphic abstract


2017 ◽  
Vol 14 (2) ◽  
pp. 152-162 ◽  
Author(s):  
Yan Chen ◽  
Hongmei Chen ◽  
Yochai Birnbaum ◽  
Manjyot K Nanhwan ◽  
Mandeep Bajaj ◽  
...  

Purpose: To assess the effects of Aleglitazar on hyperglycaemia-induced apoptosis. Methods: We incubated human cardiomyocytes, cardiomyocytes from cardiac-specific peroxisome proliferator-activated receptor-γ knockout or wild-type mice in normoglycaemic or hyperglycaemic conditions (glucose 25 mM). Cells were treated with different concentrations of Aleglitazar for 48 h. We measured viability, apoptosis, caspase-3 activity, cytochrome-C release, total antioxidant capacity and reactive oxygen species formation in the treated cardiomyocytes. Human cardiomyocytes were transfected with short interfering RNA against peroxisome proliferator-activated receptor-α or peroxisome proliferator-activated receptor-γ. Results: Aleglitazar attenuated hyperglycaemia-induced apoptosis, caspase-3 activity and cytochrome-C release and increased viability in human cardiomyocyte, cardiomyocytes from cardiac-specific peroxisome proliferator-activated receptor-γ knockout and wild-type mice. Hyperglycaemia reduced the antioxidant capacity and Aleglitazar significantly blunted this effect. Hyperglycaemia-induced reactive oxygen species production was attenuated by Aleglitazar in both human cardiomyocyte and wild-type mice cardiomyocytes. Aleglitazar improved cell viability in cells exposed to hyperglycaemia. The protective effect was partially blocked by short interfering RNA against peroxisome proliferator-activated receptor-α alone and short interfering RNA against peroxisome proliferator-activated receptor-γ alone and completely blocked by short interfering RNA to both peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-γ. Conclusion: Aleglitazar protects cardiomyocytes against hyperglycaemia-induced apoptosis by combined activation of both peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-γ in a short-term vitro model.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
KyeongJin Kim ◽  
Jin Ku Kang ◽  
Young Hoon Jung ◽  
Sang Bae Lee ◽  
Raffaela Rametta ◽  
...  

AbstractIncreased adiposity confers risk for systemic insulin resistance and type 2 diabetes (T2D), but mechanisms underlying this pathogenic inter-organ crosstalk are incompletely understood. We find PHLPP2 (PH domain and leucine rich repeat protein phosphatase 2), recently identified as the Akt Ser473 phosphatase, to be increased in adipocytes from obese mice. To identify the functional consequence of increased adipocyte PHLPP2 in obese mice, we generated adipocyte-specific PHLPP2 knockout (A-PHLPP2) mice. A-PHLPP2 mice show normal adiposity and glucose metabolism when fed a normal chow diet, but reduced adiposity and improved whole-body glucose tolerance as compared to Cre- controls with high-fat diet (HFD) feeding. Notably, HFD-fed A-PHLPP2 mice show increased HSL phosphorylation, leading to increased lipolysis in vitro and in vivo. Mobilized adipocyte fatty acids are oxidized, leading to increased peroxisome proliferator-activated receptor alpha (PPARα)-dependent adiponectin secretion, which in turn increases hepatic fatty acid oxidation to ameliorate obesity-induced fatty liver. Consistently, adipose PHLPP2 expression is negatively correlated with serum adiponectin levels in obese humans. Overall, these data implicate an adipocyte PHLPP2-HSL-PPARα signaling axis to regulate systemic glucose and lipid homeostasis, and suggest that excess adipocyte PHLPP2 explains decreased adiponectin secretion and downstream metabolic consequence in obesity.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei Zhu ◽  
Hongyang Zhao ◽  
Fenfen Xu ◽  
Bin Huang ◽  
Xiaojing Dai ◽  
...  

Abstract Background Fenofibrate is a fibric acid derivative known to have a lipid-lowering effect. Although fenofibrate-induced peroxisome proliferator-activated receptor alpha (PPARα) transcription activation has been shown to play an important role in the malignant progression of gliomas, the underlying mechanisms are poorly understood. Methods In this study, we analyzed TCGA database and found that there was a significant negative correlation between the long noncoding RNA (lncRNA) HOTAIR and PPARα. Then, we explored the molecular mechanism by which lncRNA HOTAIR regulates PPARα in cell lines in vitro and in a nude mouse glioma model in vivo and explored the effect of the combined application of HOTAIR knockdown and fenofibrate treatment on glioma invasion. Results For the first time, it was shown that after knockdown of the expression of HOTAIR in gliomas, the expression of PPARα was significantly upregulated, and the invasion and proliferation ability of gliomas were obviously inhibited. Then, glioma cells were treated with both the PPARα agonist fenofibrate and si-HOTAIR, and the results showed that the proliferation and invasion of glioma cells were significantly inhibited. Conclusions Our results suggest that HOTAIR can negatively regulate the expression of PPARα and that the combination of fenofibrate and si-HOTAIR treatment can significantly inhibit the progression of gliomas. This introduces new ideas for the treatment of gliomas.


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